Get rid of the "Reddit Premium" advert by using Stylus.

A way to get rid of Reddit Premium ad, You have to install Stylus for Chrome and Firefox.

Link: Remove Premium ad in Old Reddit (Note: It works only on the Old Reddit.)

How to Get the Old Reddit (Pre-2018 Design)

There is a way to revert back to the old pre-2018 Reddit design.

Extensions to install:
Tampermonkey (Chrome, Firefox)

Tampermonkey Scripts:
Reddit Favicon Revert
Reddit Old Layout

Note: We can get rid of the Premium Ad by installing this.

How to Get the Old 2014 YouTube Layout Design!

There is a way to get the old mid-2014 YouTube design.

Extensions to install:
Ublock Origin (Chrome, Firefox)
Tampermonkey (Chrome, Firefox)
Stylus (Chrome, Firefox)

Filter these in Ublock Origin:
www.youtube.com###trending-guide-item > .spf-link.yt-valign.yt-uix-sessionlink.guide-item
www.youtube.com###unlimited-guide-item > .spf-link.yt-valign.yt-uix-sessionlink.guide-item
www.youtube.com##.spf-nolink.yt-valign.yt-uix-sessionlink.guide-item
www.youtube.com##.ytp-ce-element

Tampermonkey Scripts:
YouTube - Restore Classic
YouTube - Autoplay Disabler

Get these styles here:
YouTube Arial Style Font
YouTube Mid-2014 Sidebar
YouTube Revert Mid-2014 Pages
YouTube 2014 Player
Disable autohide in YT player

A fix for the watch page on resolutions:
Fix Watch Sidebar: 639px or 853px
Fix Secondary Actions: 325px or 545px

Screenshots:
Homepage with not logged in
Homepage with logged in
Search results
Watch page
Channel page

Notes:

• There is a bug with a "Watch later" button not showing the icon.
• If you are on a watch page, They glitched up the watch sidebar along with secondary actions.
• Also, the sidebar code inculdes the early-2014 Subscribe button.

UPDATE 2020-Feb-18: YouTube will stop supporting the older version by March this year. So, things didn't work with the new design...